Many patients are unaware that electronic anti-theft systems, also known as electronic article surveillance (EAS) systems, can pose a threat to people using cardiac devices, they said.

Prolonged exposure to the in-store devices can cause pacing therapy to drop beats and cause implantable defibrillators (ICDs) to deliver inappropriate shocks. While previous warnings have been issued, many patients are unaware of the problem.

It is particularly important that patients do not sit or slouch in a chair or couch in store entry areas. Some of the anti-theft devices are hidden under floors, in walls and in doors.